leetcode

Data Structure II: Day 15

2 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/ Problems/0105.cpp b/ Problems/0105.cpp

@@ -0,0 +1,31 @@

class Solution {

typedef vector<int>::iterator vii;

struct Record {

TreeNode **fill = nullptr;

vii start, end;

Record(TreeNode **f, vii s, vii e) : fill(f), start(s), end(e) {}

};

public:

TreeNode *buildTree(vector<int> &preorder, vector<int> &inorder) {

stack<Record> st;

TreeNode head;

int pre = 0;

st.push({&head.right, inorder.begin(), inorder.end()});

while (!st.empty()) {

Record r = st.top();

st.pop();

while (r.start < r.end) {

vii mid = find(r.start, r.end, preorder[pre]);

if (mid == r.end) break;

TreeNode *n = *r.fill = new TreeNode(preorder[pre++]);

st.push({&n->right, next(mid), r.end});

r.end = mid;

r.fill = &n->left;

}

}

return head.right;

}

};

diff --git a/ README.md b/ README.md

@@ -97,6 +97,7 @@ for solving problems. | 0102 | Medium | [Binary Tree Level Order Traversal](Problems/0102.cpp) | | 0103 | Medium | [Binary Tree Zigzag Level Order Traversal](Problems/0103.cpp) | | 0104 | Easy | [Maximum Depth of Binary Tree](Problems/0104.cpp) |

| 0105 | Medium | [Construct Binary Tree from Preorder and Inorder Traversal](Problems/0105.cpp) |

| 0107 | Medium | [Binary Tree Level Order Traversal II](Problems/0107.cpp) | | 0108 | Easy | [Convert Sorted Array to Binary Search Tree](Problems/0108.cpp) | | 0109 | Medium | [Convert Sorted List to Binary Search Tree](Problems/0109.cpp) |